Circuit/System Description
WARNING: This page is about a different car, the 2010 Cadillac STS. However, it is still accessible from the selected car via links, so may be relevant.
The traction control indicator is controlled by the instrument panel cluster (IPC) via serial data messages from the instrument panel module (IPM) or electronic brake control module (EBCM). The traction control indicator will be illuminated when the traction control switch is applied and the traction control system (TCS) will be disabled for the remainder of the ignition cycle or until the system is enabled by the switch.
The EBCM sends a serial data message to the instrument panel cluster to illuminate the traction control indicator when the EBCM has disabled the traction control system due to a DTC. The traction control indicator will also turn ON during the instrument cluster bulb check for 3 seconds and then turn OFF.